On the other hand, if what you want is to obtain the difference
between two different times, then you could use the procedure
time-difference, as in:

500 Can't connect to 127.0.0.1:8778 (connect: Connection refused)

The example above, as you surely guessed, returns the values 0, and
3000, which represent the nano-seconds, and seconds in the
difference of the input times, respectively. However, note that the
return value of time-difference is an instance of the time type.

Important note: It is an error if the times passed as arguments to
time-difference are of different time types.

Furthermore, and having into consideration the time duration type,
you can also add, or subtract to a given time directly (instead of
adding seconds). In this case, you can use any kind of time as input.